Also, paying someone to care about it as much as you do may be out of your wallet (well, perhaps not the case for SV devs reading).
The attention to detail and actual time that you are willing to put into your own home is just different from someone for whom it's just another job.
Good ripple effects.
My wife has not only embraced me doing more things around the house (and to me, this is getting to do more things) as she's seen what I can do, but she's also embraced her own capabilities more as she's discovered what she can do.
There's also cases where professionals have different skill levels, or just a bad day, and make mistakes working on your issue. But when you did the initial build or repair yourself, you often learn enough to come in and troubleshoot an issue that arises, without having to schedule a troubleshooting session (or five, as is the case of my brand new roof that still has a new leak after quite a few visits and failure to identify the cause.)
The more capable you find yourself, the more you can readily learn to shape your immediate environment to be the world you want to live in. And arguably, there's more satisfaction in that than paying others to shape the world for you.